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WEATHER. AIR MASS. huge mass of air with similar temperature and humidity characteristics. huge section of the troposphere in which the temperature and humidity are fairly uniform at any given level. name an air mass from its temperature and humidity. SOURCE REGION.
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AIR MASS huge mass of air with similartemperature and humidity characteristics huge section of the troposphere in which the temperature and humidity are fairly uniform at any given level name an air mass from itstemperature and humidity
SOURCE REGION location over which an air mass sitsand acquires itstemperature and humiditycharacteristics
two broad types of surfaces on earth: waterland the humidity characteristic of an air mass comes from the type of surface of the source region water = moist land = dry maritime continental m c
temperature comes from latitude of the source region equatorial E hot tropical T warm polar P cool or cold arctic A very coldantarctic AA
humidity temperature m, c E, T, P, A mE cE mT cT mP cP mA cA 6 8 NAME AN AIR MASS=one of these six choices
AIR MASS SOURCE REGIONSNorth America cP-cA mP mP cP mT cT mT mT
the characteristics of an air mass dominate the weather of locations within the air mass cE--hot and dry cT--warm and dry mT--warm and moist cP--cool or cold and dry mP--cool or cold and moist cA--very cold and dry air mass weather--dominated by an air mass
air masses move away from their source regions FRONT boundary between two different air masses
the earth’s rotation makes a frontal boundary surface a gentle slope warm air is less dense than cold, so the warm air rises over the colder, denser air
4 TYPES OF FRONTS warm front--warm air moves in to replace cold cold front--cold air moves in to replace warm stationary front--boundary between two different air masses which is not moving appreciably occluded front--more complex, to be defined later
cold air cold front cold air warm front warm air warm air cold air stationary front warm air occluded front weather map symbols N
cumulonimbus cold air warm air Cross-Section of a Cold Front
the polar northeasterlies begin to push the air mass southward, and the prevailing southwesterlies begin to push an air mass northward
stationary front polar front L cold warm L cold warm
L L cold cold warm warm repeated illustration for comparison
polar front L cold warm L L cold cold warm warm Middle Latitude Cyclone
L cold warm OCCLUDED FRONT map view cross-section cold air cool air surface cold-front type occlusion
L cumulonimbus cold cold air warm MAP VIEW Cross-Section of Middle Latitude Cyclone with center of the low to the north
cold air cumulonimbus The Process of OCCLUSION